Some printing systems form a printed image by ejecting ink from ink printheads. Thereby, ink is applied onto the print medium for printing a pattern of individual dots at particular locations of an array defined for the printing medium. The printed pattern reproduces an image on the printing medium. At least some of these printing systems are commonly referred to as inkjet printers.
A fixer fluid may be used for improving print quality of a printed pattern. In particular, a fixer fluid may address coalescence, bleed, or similar effects characterized by ink or pigment migration across a printed surface. A printing system may include a treatment printhead configured to eject a fixer fluid. The treatment printhead applies the fixer fluid by ejecting the fixer over the particular locations for ink placement. Thereby, the fixer treats ink on the print medium in order to prevent coalescence, bleed, or similar effects. The fixer fluid may be applied before, after or, quasi-simultaneously to the application of the ink.
Accurate application of the fixer fluid on the particular locations for ink placement improves print quality since, otherwise, ink on the print medium may remain untreated. Misalignment of a treatment printhead may compromise an accurate application of the fixer fluid. Therefore, methods and systems for estimating whether a treatment printhead is misaligned are desirable. Further, a misalignment estimation may be used for quantifying the misalignment of the treatment printhead and, eventually, correcting misalignment of a treatment printhead in subsequent printing.